ToolTalk

ToolTalk. It is an inter-process communication (IPC) and message passing system developed by Sun Microsystems in the early 1990s. The system was designed to enable independent software applications to communicate and collaborate seamlessly across a network in a distributed computing environment. It became a core component of the Common Desktop Environment (CDE) and was integral to the Open Software Foundation's Distributed Computing Environment (DCE) framework.

Overview

ToolTalk provided a high-level, language-independent messaging service that allowed applications to announce their capabilities and request services from other programs without direct knowledge of each other. This facilitated a component-based software architecture where tools could cooperate dynamically. The system was particularly influential in Unix-based workstation environments, promoting integration between disparate applications from vendors like IBM, Hewlett-Packard, and Silicon Graphics. Its design emphasized reliability and network transparency, enabling communication between processes on the same host computer or across a local area network.

Architecture

The architecture centered on a persistent, centralized message server known as the *ToolTalk daemon* (`rpc.ttdbserver`), which used Remote Procedure Call (RPC) for communication. Messages were classified into either *notices*, which were announcements sent without expectation of a reply, or *requests*, which solicited a response from a receiving process. Applications could register *patterns* with the daemon to declare their interest in specific types of messages. The system employed an object-oriented data model, with messages containing attributes like the sending *process*, a *session* identifier, and the addressed *object*. This structure was managed through the ToolTalk API, which provided functions for message composition, dispatch, and reception.

Implementation and usage

Implementation was primarily in the C (programming language) and was tightly integrated with the Solaris (operating system) and the Common Desktop Environment. Developers used the API to make their applications "ToolTalk-aware," enabling features like compound document interactions, where a change in a graphics editor could automatically update a containing document in a separate word processor. The system managed complex operations such as message queuing, delivery guarantees, and session management. Key usage examples included integration within the CDE desktop tools, collaboration features in FrameMaker, and workflow automation in engineering software from companies like Autodesk.

Interoperability and standards

ToolTalk was positioned as an open standard to foster interoperability among Unix vendors. It was adopted as part of the Common Desktop Environment specification by the Common Open Software Environment (COSE) consortium, which included Sun Microsystems, IBM, Hewlett-Packard, Novell, and Santa Cruz Operation. The messaging protocol itself was based on ONC RPC, promoting network transparency. While it competed with other IPC mechanisms like the Object Management Group's CORBA and Microsoft's Object Linking and Embedding (OLE), its integration into CDE ensured its widespread deployment on commercial Unix systems throughout the 1990s.

History and development

Development began at Sun Microsystems in the late 1980s, with its first major release in 1991. The technology was a strategic part of Sun's OpenWindows desktop environment and its Network File System (NFS) ecosystem. Its prominence grew with its inclusion in the Common Desktop Environment in 1993, which was adopted by most major Unix vendors following the Common Open Software Environment initiative. However, with the rise of Linux, alternative desktop environments like GNOME and KDE, and competing technologies such as D-Bus, its influence waned in the early 2000s. The final version was maintained as part of the open-source OpenSolaris project before its development was effectively discontinued.

Category:Sun Microsystems software Category:Unix inter-process communication and networking Category:Distributed computing Category:Common Desktop Environment